自密实混凝土的抗冻融性能研究

自密实混凝土是一种具有高流动性，且具有持久稳定性的混凝土。由于这类混凝土只是近年来才被广泛认可，所以关于硬化后的自密实混凝土耐久性研究非常有限,尤其是在寒冷气候条件下，为此，我们对自密实混凝土抗冻融循环的性能进行了实验室和现场试验,证明了可以生产出具有抗冻融的自密实混凝土。同时我们发现，自密实混凝土的耐久性取决于很多因素，其中包括高效减水剂和引气剂的类型等。从本文我们可以发现，高效减水剂和引气剂之间配比不同,自密实混凝土的气孔质量也不同，在自密实混凝土中,相比传统的自然松香型引气剂,使用合成型的引气剂能形成更好的气孔结构。当混凝土气泡比表面积小于24mm^2/mm^3,间隔系数大于0.20mm时,也能生产出抗冻融循环的自密实混凝土。

Frosting resistance of self-compact concrete

The perfect fluidity and stability are properties of self-compact concrete. For this kind of concrete is new material, the research on it is limited under the cold temperature condition. The anti-freezing-and-thawing circulation performance of self-compact concrete is tested in the laboratory and on the spot, the result shows the self-compact concrete with anti-freezing-and- thawing can be produced. And many factors affecting durability of self-compact concrete include types of superplasticizer and air entraining agent. Pores change with the different mixing of superplasticizer and air entraining agent. Compared with natural rosin air retraining agent, synthesized air entraining agent can form better pore structure. While the surface-to-volume ratio is lower than 24mm^2/mm^3, interval factor is more than 0.20mm, the self-compact concrete of anti-freezing-and-thawing circulation can be produced.